This invention relates to communications systems, particularly to optical communications systems such as public telephone systems which must be able to provide substantially simultaneous service to a large number of users of the system.
It is well established that fiber optics provide a promising way to enhance communications and, to some extent, fiber optics systems are even now being incorporated into communications systems. These optic systems are star-network-type systems wherein the transmitter is linked directly to the receiver or, in the case of some trunk lines, where fiber-optics are used in long-line applications as micro-wave transmission is used, i.e. in mere transmission of signals between widely-separated stations.
It has still remained a problem to provide an optical communications system which can interface efficiently with a large number of customers linked directly to a common trunk system. It is a particular problem to provide such a system for the large existing infrastructure of equipment, which is based on electroconductive signal systems, and to do so within acceptable constraints on signal selectivity, power consumption and capital cost.